Well I've gone ahead and done it now. Works like a charm. While at it, I also threw in a 2S lipo battery status display, which turns on when the flywheel motors spin. I ended up mounting the display upside down, as I hold it with right hand, and look "over" the gun when checking the display. The reason it's not on the other side is that I want all electronics to be on the bottom half of the nerf when opening it up, so there are no wires connecting the two halves, potentially snapping if someone else opens it up in the future.
Next up I think might be a speed controller potentiometer for the conveyor belt motor.